﻿using System;

namespace 谢长东
{
    class Program
    {
        static void Main(string[] args)
        {
            //常量
            const double pai = 3.14;
            int r = 2;

            double s = pai * Math.Pow(r, 2);
            double c = 2 * pai * r;
            Console.WriteLine("面积为:{0}\n周长为:{1}", s, c);


            //分支语句
            if (5 < 10)
            {
                Console.WriteLine("5小于10");
            }



            int a = 10;
            if (a > 15)
            {
                Console.WriteLine("a大于15");
            }
            else if (a > 10)
            {
                Console.WriteLine("a大于10");
            }
            else
            {
                Console.WriteLine("a小于或等于10");
            }


            Console.WriteLine("请输入第N天");
            int day = int.Parse(Console.ReadLine());
            switch (day)
            {
                case 1:
                    Console.WriteLine("吃鲍鱼");
                    break;
                case 2:
                    Console.WriteLine("吃牛排");
                    break;
                case 3:
                    Console.WriteLine("穷，吃萝卜干");
                    break;
                default:
                    Console.WriteLine("穷，吃泡面");
                    break;
            }

        }
    }
}
